Te溶剂-Bridgman法Cd0.9Mn0.1Te晶体生长习性研究

采用Te溶剂-Bridgman法生长了尺寸为φ30 mm× 60 mm的Cd0.9Mn0.1Te:In晶锭,通过淬火得到了生长界面形貌.测试了晶片在近红外波段的透过率和电阻；采用化学腐蚀的方法观察了晶片中位错,Te夹杂和孪晶界；采用光学显微镜和红外成像显微镜观察了生长界面处附近的形貌.测试结果表明,晶锭中部结晶质量较好的晶片红外透过率达到60％,电阻率达到2.828×1011Ω · cm.位错密度在106 cm-2数量级,Te夹杂密度为1.9×104 cm-2,同时孪晶密度明显低于Bridgman法生长的晶锭.生长界面宏观形貌平整,呈现微凹界面.但由于淬火过程的快速生长,界面微观形貌发生变化,呈现不规则界面,并在界面附近形成富Te相的包裹.

Study on Cd0.9Mn0.1Te Growth Behavior by Te Solvent-Bridgman Method

Cd0.9Mn0.1Te∶In crystal ingot with size of Ф30 mm×60 mm was grown through Te solvent-Bridgman method.IR transmittance and resistivity were measured to evaluate its crystalline quality.Chemical etching was applied to reveal the crystal defects,including dislocations,twins and Te inclusions.The macro-and micro-morphology of growth interface were quenched and observed with optical microscopy and infrared transmission microscopy.Te solvent-Bridgman method could effectively decline growth temperature and reduce the dislocation density in the ingot.The IR transmittance of wafers in the middle of the ingot reaches 60% and the bulk resistivity reaches 2.828×1011 Ω·cm.The EPD of a good quality wafer is about 106 cm-2,Te inclusions density measured through IR transmission microscopy is about 1.9×104 cm-2comparing with conventional Bridgman growth method.The quenched growth interface shows a slightly concaved appearance in macro-scale.However,the micro-scale interface is not smooth due to fast growth in quenching process.Meanwhile high density of Te inclusion near the interface was observed.